A wide variety of applications involve circumstances where it is desirable to move an item while also exposing it to environmental factors such as heat, radiation, cold or the like. In many instances it is also desirable to agitate the item, if it has a fluid component, in order to insure maximum and uniform exposure of the contents of the item to the environmental condition.
One area in which this sort of technology is required is in automated cooking apparatus. In these circumstances it is often necessary to agitate or stir the contents of a cooking vessel while exposing it to heat. In many cases this is necessary to achieve uniform exposure. One example of a device adapted for this purpose is a fettuccine cooking apparatus described and shown in U.S. Pat. No. 4,577,551, issued to G. Bellanca. Another is found in the oven assembly of C. M. Vaughan, shown in U.S. Pat. No. 3,232,247. These two patents show methods utilized in the prior art to heat and agitate contents at the same time.
Another area of technology which requires agitation over a period of time is in the area of biological cultures. A device for agitating liquids, particularly those contained on sample trays, is shown in U.S. Pat. No. 4,102,649, issued to T. Sasaki. A further example of a method of agitating suspended cells in liquid is found in U.S. Pat. No. 3,468,520, issued to W. J. Duryea et. al. The object of each of these devices is to create an uniformity in the solution so that all of the contents will react at a similar rate.
In some instances the desirable goal is to utilize the liquid to uniformly wet a selected surface. An example of a U.S. Patent directed to this technology is U.S. Pat. No. 3,695,162, issued to R. Wing for a "Developing Machine For Photographic Film". In the Wing application it was desired to uniformly coat the photographic film with the developing chemicals so that an even rate of development was achieved.
The present invention is directed to a somewhat similar application in the fields of Biochemistry and Microbiology. Some of the processes utilized for study of gene structure, expressions and functions in all biological systems are the analysis of DNA and RNA species by hybridization to a radio isotope-Labeled Nucleotide Probe. This process is described in an article entitled "AN ALTERNATIVE TO THE WATERBATH/PLASTIC BAG METHOD FOR HYBRIDIZATION OF SOUTHERN AND NORTHERN BLOTS", by Sabrina Bennahmias, American Biotechnology Laboratory, September, 1989.
In the hybridization process the nucleic acids are separated by electrophoresis through a gel and are mobilized by capillary transfer to sheets of nitrocellulose or nylon membrane. The separate groupings of nucleic acid, referred to as "blots", are fixed on the membrane for later processing. One of the processes which is utilized in this procedure is to the wash the membranes in a buffer solution including a radioactive material referred to as a "probe". The radioactive probe selectively hybridizes the DNA and RNA nucleic acids which are complementary to the nucleotide sequence of the selected probe.
In order to achieve complete and uniform results it is necessary that the membrane containing the blot is uniformly exposed to the probe solution so as to achieve complete hybridization. It is also necessary that the hybridization take place within specific temperature ranges. The preferred temperatures for most of the hybridization processes presently used fall in the temperature range of 42.degree. C. to 68.degree. C. Reasonably precise temperature control and uniform temperature exposure are desirable in order to obtain consistent results.
Although, in the prior art, the hybridization was frequently performed in a shaker bath or "sandwich box", these methods occasionally had difficulties regarding spillage, material handling, volumes of probe utilized and waste disposal problems. Since the probe solution is radioactive in nature, any container or contents thereof which absorb any of the probe solution must be disposed of as radioactive waste. Therefore, it has become desirable to utilize non-absorbent containers, such as high quality borosilicate glass.
When glass bottles are utilized for the hybridization procedures the most efficient method of treating them is to utilize a temperature controlled oven mechanism with sample transport and agitation means within the oven. Although water baths and other heating mechanisms may be utilized, the oven has proved to be the most efficient and easily maintained. Various commercial temperature controlled ovens have been available in the marketplace for a lengthy period of time, and have been utilized for a variety of different processes. There have also been various methods utilized to rotationally move contents through an oven, such as the oven assembly of Vaughan.
However, none of the prior art structures has successfully solved all of the problems inherent in the hybridization process. Temperature uniformity, economy of manufacture and usage, and complete and uniform wetting with a minimum quantity of probe solution are all goals which have been approached, but not as closely as desired. Therefore, substantial room for improvement remains in the field.